1. Field of the Invention
The present invention relates to bulk freight handling systems, and more particularly, to a freight cart locking system including devices for securing freight carts within vehicles to prevent damage to the vehicle and the freight during bulk product shipping by trucks, trailers, or other vehicles.
2. Background of the Invention
The type of mobile bulk freight cart which may be secured in a truck or trailer with a locking device of the present invention has been utilized for several years for carrying freight and is shown in FIG. 2 of the accompanying drawings. These carts can be readily loaded at freight terminals and can be moved directly into an outgoing delivery truck or trailer. As the driver of the vehicle makes freight deliveries, the carts may be removed from the vehicle or may be gradually emptied, and the driver can segregate his pickups into the carts as he reloads the truck or trailer. The use of these carts has been found to greatly simplify the job of the freight operator and materially enhances the commercial competitiveness of the freight handling operation.
It is necessary to provide a means for securing these carts in the truck or trailer in which they are to be transported so that they will not shift while the truck is in transit. In U.S. Pat. No. 2,950,126 to Armentrout, a mobile bin is disclosed which provides a means for securing a cart of the type described above to the side rail of a truck or trailer. The mobile bin disclosed by Armentrout requires that the cart be modified before it can be used.
Other attempts to secure carts of the type described above have included the use of bushings attached to both the side rail of the vehicle and to the upright members of the cart which are to be secured to side rail. The difference in height of these bushings on the vehicle and on the cart to be secured are such that, when aligned, a pin may be inserted through both of them. The cart is, therefore, secured to a side rail mounted inside of the walls of the vehicle, but this type of locking device also requires modification to the cart to be secured.
Other locking devices for securing articles in vehicles during transit have focused on securing the bottom portion of the freight to be transported. For example, in U.S. Pat. No. 3,399,921 to Trost et al., a spring operated latching mechanism is disclosed for enabling a container to be secured to the bin of the truck or trailer. The utilization of the Trost latching mechanism requires that the container to be secured must be specially adapted to receive the latching mechanism.
The locking device of the present invention has the advantage of eliminating the necessity of modifying the cart before it can be secured in a vehicle.